157990581 has 48 divisors (see below), whose sum is σ = 272248704. Its totient is φ = 89688384.

The previous prime is 157990577. The next prime is 157990607. The reversal of 157990581 is 185099751.

It is not a de Polignac number, because 157990581 - 2² = 157990577 is a prime.

It is a super-2 number, since 2×157990581² = 49922047369435122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157990541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 498235 + ... + 498551.

It is an arithmetic number, because the mean of its divisors is an integer number (5671848).

Almost surely, 2^157990581 is an apocalyptic number.

It is an amenable number.

157990581 is a deficient number, since it is larger than the sum of its proper divisors (114258123).

157990581 is an equidigital number, since it uses as much as digits as its factorization.

157990581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 632 (or 620 counting only the distinct ones).

The product of its (nonzero) digits is 113400, while the sum is 45.

The square root of 157990581 is about 12569.4304166895. The cubic root of 157990581 is about 540.6012746936.

The spelling of 157990581 in words is "one hundred fifty-seven million, nine hundred ninety thousand, five hundred eighty-one".